Ammonium Nitrate And Fuel Oil Research Articles

Detonability of Ammonium Nitrate Mixtures with the Addition of Organic Materials

As an oxygen carrier and a strong oxidising agent, ammonium nitrate can create an explosive mixture when mixed with organic material. A typical example is the mixture of ammonium nitrate and fuel oil (ANFO), which is the most used explosive for civilian applications. In this work, we studied the detonability and detonation properties of mixtures of ammonium nitrate with recycled rubber and hay. The main goal of this study was to determine the optimal volume ratio of ammonium nitrate and organic materials in terms of achieving the best performance (working capacity). Using small experiments, it was determined that the maximum burst velocity for the ammonium nitrate/hay mixture is achieved at 8% hay by volume, while the maximum burst velocity for the ammonium nitrate/rubber mixture is achieved at 15% rubber by volume. A thermochemical calculation has shown that the maximum detonation heat is achieved at the zero oxygen balance at the volume ratios of 89.2/10.8 for AN/Rubber and 72.85/27.15 for AN/Hay.

Evaluation of handheld Raman spectrometers for the detection of intact explosives

The detection of intact explosives in the field provides a unique challenge for investigators, considering the sensitive and dangerous nature of these samples. Handheld Raman instruments have grown in popularity for the analysis of unknown samples in the field, combining speed of data collection and reliability with a size that allows for the instruments to be field portable. Handheld Raman instruments are used commonly in the field, and yet there is very little research on the detection capabilities of these instruments, specifically for explosive compounds. The present study aimed to evaluate the detection capabilities of two handheld Raman spectrometers, the Rigaku ResQ-CQL and the Field Forensics HandyRam™, using explosives analytical standards, including 2,4,6-trinitrotoluene (TNT), nitromethane (NM), ammonium nitrate (AN) and smokeless powder components such as diphenylamine (DPA), ethyl centralite (EC), and methyl centralite (MC). The spectrometers were evaluated on their sensitivity, the repeatability of the data, and the performance of the internal library when available. In addition, an interference study with glass and plastic containers was also performed. Finally, authentic intact explosive samples, including TNT flakes, a mixture of ammonium nitrate and fuel oil (ANFO), smokeless powder and nitromethane were analyzed to evaluate the developed method and test the detection capabilities of the spectrometers with authentic samples. Spectra were reproducible for all the analytes across both instruments, with regards to the peak location and the intensity. Spectra obtained with the Rigaku ResQ-CQL displayed better resolution for all analytes, including the authentic samples. In addition, its wider scan range allowed for the detection of more detailed peaks below 400 cm−1. Identifying the detection capabilities of these handheld instruments can therefore help guide investigators on how to best utilize them in the field.

Numerical modelling of non-ideal detonation in ANFO explosives applying Wood-Kirkwood theory coupled with EXPLO5 thermochemical code

Ammonium nitrate and fuel oil (ANFO) based explosive is a classic example of non-ideal high explosives. Its detonation is characterized by a strong dependence of detonation parameters on explosive charge diameter, presence and characteristics of confinement, as well as incomplete consumption of explosive at the sonic point.In this work we propose a detonation model based on the Wood-Kirkwood (WK) theory coupled with the thermochemical code EXPLO5 and supplemented with reaction rate models. Our objective is to analyze the validity of the model for highly non-ideal ANFO explosives, with emphasis on effect of reaction rate models.It was found that both single-step and two-step pressure-based models can be calibrated to reproduce experimental detonation velocity-charge radius data of ANFO at radii significantly above the failure radius (i.e. for D/Did > ∼0.6). Single-step pressure-based model, with the pressure exponent equal to 1.4, proved to be the most accurate, even in the vicinity of the failure radius. The impact of the rate models is most evident on temporal (and spatial) distribution of flow parameters in detonation driving zone, especially when it comes to the conversion and width of detonation driving zone.

The dependence of Ammonium-Nitrate Fuel-Oil (ANFO) detonation on confinement

As detonation is a coupled fluid-chemical process, flow divergence inside the detonation reaction zone can strongly influence detonation velocity and energy release. Such divergence is responsible for the diameter-effect and failure-diameter phenomena in condensed-phase explosives and particularly dominant in detonation of nonideal explosives such as Ammonium Nitrate and Fuel Oil (ANFO). In this study, the effect of reaction zone flow divergence on ANFO detonation was explored through variation of the inert confinement and explosive diameter in the rate-stick geometry with cylinder expansion experiments. New tests are discussed and compared to prior experiments. Presented results include the detonation velocity as a function of diameter and confinement, reaction zone times, detonation product isentropes and energies, as well as sonic surface pressures and velocities. Product energy densities and isentropes were found to increase with detonation velocity, indicating more complete chemical reaction with increased detonation velocity. Detonation reaction zone times were found to scale with the acoustic transit time of the confiner wall and used to show that the ANFO diameter effect scaled with the reaction zone time for a particle along the flow centerline, regardless of the confinement. Such a result indicates that the ANFO reaction mechanisms are sufficiently slow that the centerline fluid expansion timescale is a limiting factor controlling detonation velocity and energy release.

Study of non-conventional fuels for explosives mixes

The use of ammonium nitrate and fuel oil (ANFO) results in low cost blasting. Such costs may be further reduced by replacing fuel oil with alternative fuels such as biomass (biodiesel, rice straw, corn cob, sugar cane bagasse) and tires residue. This paper investigates the use of other fuels instead of fuel oil by measuring the detonation velocity (VOD) and verifying the importance of these fuels in an explosive mixture. Except for biodiesel, all the tests conducted for the mixture of ammonium nitrate and alternative fuels showed poor performance when compared with ANFO. The achieved percentage of detonation velocity (VOD) of the mixtures in relation to the ANFO were 55.4% for ammonium nitrate + rice straw, 64.9% for ammonium nitrate + corn cob, 70.1% for ammonium nitrate + sugar cane bagasse, 74.4% for ammonium nitrate + tires residue and 93.7% for ammonium nitrate + biodiesel. This study indicates that the methodology proposed can be applied as a reference for determination and preparation of explosive mixtures of fuel and oxidizing agents since in all the tests conducted the detonation of the charges occurred.

YSZ-Based Electrochemical Gas Sensors for the Detection of Explosives

A zirconia-based mixed potential sensor utilizing dense lanthanum chromite and Pt electrodes and porous YSZ electrolyte was used in an alternating HC mode (unbiased) and total NOx mode (50 nA bias current applied) to detect the HC and NOx deflagration remnants of a nitroglycerin/nitrocellulose propellant (Bullseye{trade mark, serif}), ANFO (ammonium nitrate and fuel oil), blackpowder, and urea (a common, high nitrogen content fertilizer.) Unique HC and NOx sensor responses taken together with sufficient sensitivity to detect microgram quantities of Bullseye{trade mark, serif} - both directly and via capture of trace residue by swiping contaminated surfaces- suggest that detection and discrimination of HE using zirconia-based mixed potentials is possible.

Explosive welding of metal plates

This paper describes a study of explosive welding of metal plates. The properties of a locally prepared mix of 77/23 ammonium nitrate and fuel oil (ANFO) explosive and the dynamics of the plates are investigated and the results from welding tests presented. The strength of the clad plates is measured and ultrasonic inspection performed to identify and locate defects. The welding process is simulated using a finite element-based computer model. A brief description of the modeling process is given along with the results from the simulations for comparison with measured parameters.

STUDY ON THE APPLICATION OF BLASTING FOR GREENING THE DESERT

Blasting has the possibility of creating a soil area for greening the rock desert because blasting with ANFO (Ammonium Nitrate and Fuel Oil) could make rock into soil level particles (less than 2mm) and diffuse unreacted ammonium nitrate into particles as nourishment for plants. We conducted lab-scale experiments with 30 cm cubic model of rock and field experiments on the quarry to investigate relationships between blasting conditions and performances of the fragmentation of rock into soil level particles and the diffusion of nutritional ions. As results of lab-scale experiments, it was investigated that the fragmentation performance and diffusion of nutritional ions be controlled by loading conditions and that amount of ions change with the solidity of rocks because of the changes of detonation velocity. And as results of field experiment, two aspects were indicated. One was that we must suppose the new blasting method to remain sufficient amount of particles in the crater because most fragments spread around the crater. The other was that the particles after blasting contained various nutritional ions with the ANFO, added with the fertilizer.

Influence of physical properties of ammonium nitrate on the detonation behaviour of ANFO

Abstract In order to obtain a better understanding of the non-ideal detonation behaviour of ammonium nitrate based explosives, detonation velocities of ANFO (ammonium nitrate and fuel oil) prepared with different kinds of ammonium nitrate (AN) were measured in steel tubes. In this series of test six kinds of AN were used and the influence of the pore diameter, the pore volume and the particle diameter of the AN particle on the detonation velocity of ANFO was investigated. It was found that the pore diameter and the pore volume had a strong influence on the detonation velocities of ANFO. In the case of ANFO samples which were prepared with AN that had the same pore diameter and the pore volume, when tested the highest detonation velocity (3.85 km/s) was observed when the smallest particle diameter ( The 12 months aging showed the change of the detonation velocities of ANFO and the reaction of ANFO was influenced both by the physical and the chemical properties of AN particles and oil during the storage period.

EVALUATING THE EFFECT OF THE INITIATION METHOD ON BLASTING BY SEISMOGRAPHIC MONITORING AND IMAGE ANALYSIS

Mineral Resources EngineeringVol. 09, No. 04, pp. 429-436 (2000) No AccessEVALUATING THE EFFECT OF THE INITIATION METHOD ON BLASTING BY SEISMOGRAPHIC MONITORING AND IMAGE ANALYSISJORGE LUIS BROWN SEGUI, JAIR CARLOS KOPPE, and JOÃO FELIPE COIMBRA LEITE COSTAJORGE LUIS BROWN SEGUIMining Engineering Department, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99/504, 90.035-190 Porto Alegre, Rio Grande do Sul, Brazil Search for more papers by this author , JAIR CARLOS KOPPEMining Engineering Department, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99/504, 90.035-190 Porto Alegre, Rio Grande do Sul, Brazil Search for more papers by this author , and JOÃO FELIPE COIMBRA LEITE COSTAMining Engineering Department, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99/504, 90.035-190 Porto Alegre, Rio Grande do Sul, Brazil Search for more papers by this author https://doi.org/10.1142/S0950609800000366Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractExplosives performance depend on how the chemical energy available in the explosive mass is released and consequently, transferred to the rock mass. The initiation method is one of the uttermost importance in this process. This paper analyses the influence of two distinct methods of initiation, i.e. top side and point initiation in the blasting results. Ammonium nitrate and fuel oil (ANFO) detonation is highly sensitive to the way it is initiated. As ANFO is the most common explosive in open pit mining, it was chosen for comparing the initiation methods. Different blasts were monitored using a triaxial electronic seismograph. Image analysis complements the monitoring program, providing the information to compare different shots. A case study illustrates the methodology used for data acquisition. Experimental results proved the superior efficiency of point initiation and showed a reliable method of evaluate explosive performance. FiguresReferencesRelatedDetails Recommended Vol. 09, No. 04 Metrics History PDF download

Evaluating the Effect of the Initiation Method on Blasting by Seismographic Monitoring and Image Analysis

Mineral Resources EngineeringVol. 09, No. 04, pp. 429-436 (2000) No AccessEVALUATING THE EFFECT OF THE INITIATION METHOD ON BLASTING BY SEISMOGRAPHIC MONITORING AND IMAGE ANALYSISJORGE LUIS BROWN SEGUI, JAIR CARLOS KOPPE, and JOÃO FELIPE COIMBRA LEITE COSTAJORGE LUIS BROWN SEGUIMining Engineering Department, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99/504, 90.035-190 Porto Alegre, Rio Grande do Sul, Brazil Search for more papers by this author , JAIR CARLOS KOPPEMining Engineering Department, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99/504, 90.035-190 Porto Alegre, Rio Grande do Sul, Brazil Search for more papers by this author , and JOÃO FELIPE COIMBRA LEITE COSTAMining Engineering Department, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99/504, 90.035-190 Porto Alegre, Rio Grande do Sul, Brazil Search for more papers by this author https://doi.org/10.1142/S0950609800000366Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractExplosives performance depend on how the chemical energy available in the explosive mass is released and consequently, transferred to the rock mass. The initiation method is one of the uttermost importance in this process. This paper analyses the influence of two distinct methods of initiation, i.e. top side and point initiation in the blasting results. Ammonium nitrate and fuel oil (ANFO) detonation is highly sensitive to the way it is initiated. As ANFO is the most common explosive in open pit mining, it was chosen for comparing the initiation methods. Different blasts were monitored using a triaxial electronic seismograph. Image analysis complements the monitoring program, providing the information to compare different shots. A case study illustrates the methodology used for data acquisition. Experimental results proved the superior efficiency of point initiation and showed a reliable method of evaluate explosive performance. FiguresReferencesRelatedDetails Recommended Vol. 09, No. 04 Metrics History PDF download

DOE Non‐Proliferation Experiment includes seismic data

The U.S. Department of Energy detonated approximately 1.29 million kg of a commercial blasting agent, based on ammonium nitrate and fuel oil (ANFO), at the Nevada Test Site (NTS) on September 22, 1993, at 00:01.080 a.m. Pacific Daylight Time. The blasting agent was emplaced in a cylindrical chamber, approximately 15.2 m in diameter × 5.5 m high, located at 37.20193°N and 116.20986°E in a Rainier Mesa tunnel, 390 m underground. Code‐named the Non‐Proliferation Experiment (NPE), the explosion had an energy release of approximately 1 kt (1 kiloton = 4.186×1012 joules).

Nonlinear wave fronts and ionospheric irregularities observed by HF sounding over a powerful acoustic source

Different wave fronts affected by significant nonlinearities have been observed in the ionosphere by a pulsed HF sounding experiment at a distance of 38 km from the source point of a 4800‐kg ammonium nitrate and fuel oil (ANFO) explosion on the ground. These wave fronts are revealed by partial reflections of the radio sounding waves. A small‐scale irregular structure has been generated by a first wave front at the level of a sporadic E layer which characterized the ionosphere at the time of the experiment. The time scale of these fluctuations is about 1 to 2 s; its lifetime is about 2 min. Similar irregularities were also observed at the level of a second wave front in the F region. This structure appears also as diffusion on a continuous wave sounding at horizontal distances of the order of 200 km from the source. In contrast, a third front unaffected by irregularities may originate from the lowest layers of the ionosphere or from a supersonic wave front propagating at the base of the thermosphere. The origin of these structures is discussed.

Ionospheric research opportunity

Ground‐based explosions have been exploited successfully in the past as a relatively controlled source for producing ionospheric disturbances. On June 25, the Defense Nuclear Agency will conduct a high explosives test on the northern section of the White Sands Missile Range. Approximately 4,800 tons of ammonium nitrate and fuel oil (ANFO) will be detonated at ground level, producing an acoustic shock wave with a surface pressure change of approximately 20 mbar at a 6 km range. This shock front will have sufficient strength to propagate into the ionosphere with at least a 10% change in the ambient pressure across the disturbance front in the lower F region. Such an ionospheric perturbation will give ionospheric researchers an excellent opportunity to investigate acoustic propagation at ionospheric heights, shock dissipation effect, the ion‐neutral coupling process, acoustic‐gravity wave (traveling ionospheric disturbance) generation mechanisms, and associated RF phenomena.